On 3/15/2013 4:57 PM, WM wrote:> On 15 Mrz., 21:01, Virgil <vir...@ligriv.com> wrote:>> In article>> <c4fcdc68-76bb-4df0-a2f5-73d117d0b...@m4g2000vbo.googlegroups.com>,>>>>>>>>>>>> WM <mueck...@rz.fh-augsburg.de> wrote:>>> On 14 Mrz., 23:54, fom <fomJ...@nyms.net> wrote:>>>> On 3/14/2013 5:47 PM, WM wrote:>>>>>>> On 14 Mrz., 23:16, fom <fomJ...@nyms.net> wrote:>>>>>>>> "... an element of T is not a set...">>>>>>> Let T = {{a}, {b,c}, {c,d,e,f}}>>>>> then T has three elements, each of which is a set. That is common use>>>>> in modern set theory and has been used 100 years ago in the same sense>>>>> by Zermelo.>>>>>> I am well aware of modern usage.>>>>> Zermelo used it already 100 years ago.>>>>>> Unless my translation is in error, Zermelo's>>>> 1908 supports urelements.>>>>> Zermelo says (in your translation on p. 210, 3rd line): If T is a set>>> whose elements M, N, R, ... all are sets different from the null>>> set, ...>>>> That, even if accurate, in no way refutes that Zermelo allowed sets to>> contain ur-elements.>> That is not under discussion and therefore not refuted.>> fom said: an element of T is not a set> Zermelo said: T is a set whose elements M, N, R,